Structure of high elevation forests in Katunsky Range (the Altai Mountains)

Abstract

High elevation forests are both a good natural object for studying the forest dynamics and a sensitive indicator of the impact of various external factors on them. These forests on the Katunsky Range of the Altai Mountains have been studied extremely poorly. The purpose of the work is to describe the size and age structure of tree stands of forest communities and to reveal the effect of environmental factors on them in the upper part of the forest belt of the Katunsky Range (the Altai Mountains) using the Akkem glacial basin as an example. Six sample areas of 0.05-0.12 ha were used at two altitude levels (2065-2080 and 2220-2240 m a.s.l.). A total of 232 adult trees and 209 saplings and seedlings were examined, aged 86 and 180, respectively. The size and age structure of the forest stand and saplings and seedlings has been established. Three main generations of trees that established on the valley slopes have been identified in the forest stand (the first generation is trees of 530-580 years old, the second is the trees of 270-410 years old, and the third is trees of 30-120 years old) and one additional generation (130-170 years old). They established at the end of the Medieval warming (XV-XVI centuries), during the Little Ice Age (XVII-mid-XIX centuries), and during the warming which began in the mid-XIX centuries. Factors have been identified that limit the spread and the structure of the high elevation forests: geomorphological, wildfires, logging.